Ti/Al Based Ohmic Contact to As-Grown N-Polar GaN  

作　　者：冯志红 王现彬 王丽 吕元杰 房玉龙 敦少博 赵正平 

机构地区：[1]National hey Laboratory of Application Specific Integrated Circuit (ASIC), Hebei Semiconductor Research Institute Shijiazhuang 050051 [2]School of Information Engineering, Hebei University of Technology, Tianjin 300019 [3]Information Center of Science and Technology, Beijing 100085

出　　处：《Chinese Physics Letters》2015年第8期132-134,共3页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant No 61306113

摘　　要：Ti/Al based Ohmic contacts to as-grown N-polar GaN are investigated by cross-section transmission electron microscopy and energy dispersive x-ray spectroscopy. Due to the higher oxygen background doping in the N- polar GaN, the A1 metal in Ohmic stacks is found to react with background oxygen more easily, resulting in more AlOe. In addition, the formation of AlOx is affected by the A1 layer thickness greatly. The AlOx combined with the presence of AIN is detrimental to the Ohmic contacts for N-polar GaN compared with Ga-polar GaN. With the reduction of the AI layer thickness to some extent, less AlOx and AIN are formed, and lower Ohmic contact resistance is obtained. The lowest contact resistivity p of 1.97 × 10-6 Ω·cm2 is achieved with the AI layer thickness of 80 nm.Ti/Al based Ohmic contacts to as-grown N-polar GaN are investigated by cross-section transmission electron microscopy and energy dispersive x-ray spectroscopy. Due to the higher oxygen background doping in the N- polar GaN, the A1 metal in Ohmic stacks is found to react with background oxygen more easily, resulting in more AlOe. In addition, the formation of AlOx is affected by the A1 layer thickness greatly. The AlOx combined with the presence of AIN is detrimental to the Ohmic contacts for N-polar GaN compared with Ga-polar GaN. With the reduction of the AI layer thickness to some extent, less AlOx and AIN are formed, and lower Ohmic contact resistance is obtained. The lowest contact resistivity p of 1.97 × 10-6 Ω·cm2 is achieved with the AI layer thickness of 80 nm.

关 键 词：GAN AL Ti/Al Based Ohmic Contact to As-Grown N-Polar GaN As 

分 类 号：TQ133.51[化学工程—无机化工]